Device producing hammering

ABSTRACT

A hammering device comprising a body ( 1 ) from which the device can be connected to a working machine, for instance, a stroke-transmitting piece ( 5 ) fixed in the body and taking the strokes of moving and hammering mass ( 2 ) and transmitting the strokes to pile ( 7 ) to be hammered into or pulled up from the ground, whereby between piece ( 5 ) and pile ( 7 ) a clamp ( 6 ) is applied, by means of which pile ( 7 ) surface is grasped. The device includes mass ( 2 ) moving cylinders ( 8 ), by means of which the back-motion of the mass can be carried out conducting the fluid pressure to have effect on piston ( 16 ) of said cylinders on primary side ( 20 ), and by means of which cylinders the hammering motion of mass can be carried out compressing the gas on the secondary side of cylinders 8 into wanted pressure by means of fluid pressure conducted to primary side ( 20 ), whereby hammering motion is carried out discharging the fluid pressure from primary side of the cylinders.

The invention relates to a hammering device comprising a body, fromwhich the device can be connected, for instance, to a working machine, astroke-transmitting piece in the body taking the strokes of a moving andhammering mass and transmitting the strokes to a pile or similar to behammered into or pulled up from the ground, or to a tool, in whichdevice between the piece and the pile and the tool a clamp is applied,by means of which the pile or tool is grasped.

Previously known, among other things, from U.S. Pat. No. 5,765,651, is adevice driving a pile into the ground and also pulling it out, to whichstriking motion upward and downward is given by means of steam orpressure water. The pipe to be driven into ground is placed to travelthrough the mass centre hole. There are in connection with the masscylinders or similar in order to produce back motion and striking motionto the mass in both directions. The strking surface of mass meets thering-shaped counter parts, which are wedged to remain around the pipe,whereby the stroke is transmitted to the pipe.

The disadvantage of the U.S. Pat. No. 5,765,651 solution is smallcapacity, small size of impact surfaces and the lack of proper controlif the pipe is grasped from its head so that the pipe is inside the massnot steering the motion of mass. The motion cylinder arrangement withits symmetric motions in both directions gives the mass quite a slowspeed, since into the cylinders water or steam must be conducted throughvalves all the time during the motion. Thus the use of pressurized steamdoes not make even the motion faster, since steam must be conductedthrough a valve to the cylinder, where pressure is low in the firststage due to former direction of motion. Also the vibration is strongdue to back and forth motion of the symmetric mass. The speed of backmotion is as fast as the speed of the stroke motion. The back motionmust be stopped without stroke, which causes inconvenient vibration inthe device. If the back motion is made still lower by means of valves,the striking frequency remains modest.

In order to eliminate the above presented disadvantages a new hammeringdevice using movable mass which is well suited for hammering piles intothe ground and to pull them up and allows attaching tools to it, as acrushing hammer, and work with those tools. As to its hammeringfrequency the device is fast and its Stroke energy adjustable. Thehammering device as per the invention is characterized in that thedevice includes mass moving motion cylinders, by means of which the massback motion can be carried out conducting liquid pressure to have aneffect on the cylinder piston on the primary side of the cylinders, andby means of which cylinders the mass impact motion can be carried outcompress sing the gas on the secondary side of the cylinders to wantedpressure by means of fluid pressure conducted to the primary side,whereby striking motion can be produced in discharging the liquidpressure from the primary side of the cylinders.

The advantage of the hammering device as per this invention is that thehammering energy is easily regulated to a wanted value. Regulation ispossible even by remote control. Acceleration of mass takes placeoptimally. Into the cylinder that causes the striking motion no mediumat all is conducted, so the motion gets fast, when in the cylinderswelling of high-pressure gases only takes place during back motion Theinconvenient vibrations of the device can be made reduced, when thecylinder piston is by the force of primary side liquid pressure forcedto compress the gas space into a smaller size and to increase itspressure. In the final stage of compression it easy to make the pistonmotion slower by valve control and not only the slowing due to this inthe final stage of back motion does hardly lengthen the time spent forback motion. There are hammering tools easily attachable to the clampingmeans instead of piles.

In the following the invention is disclosed with reference to theenclosed figures, where

FIG. 1 shows the device cross-cut from one side hammering a pile intothe ground.

FIG. 2 shows the device cross-cut from one side hammering a pile up fromthe ground.

FIG. 3 shows increase of pressure on cylinder secondary side as functionof the piston.

FIG. 4 shows a secondary mass moving inside the piston.

FIG. 1 is a hammering device fixed to the boom head of an excavator,which assembly is made by means of fixing components 12 included in thedevice. The hammering device comprises a body 1 and inside it a hammergear is arranged by means of damping/flexible elements 3. The hammeringmachine has a mass 2 and cylinders 8 moving it. The other cylinder endsare fixed to the body connection beam 21 and the other ends to mass 2.In the other mass end thereis a striking surface 18 hammering strikingsurface 19 of counter piece 5. Counter piece 5 has a clamping device 6working by wedge principle in a manner known per se, which tightensaround pile 7. Clamping device 6 can, for instance, be opened andtightened by a hydraulic arrangement, whereby change of grip in thepile, detachments and fixings can be easily done from the cabin. piece5. Counter piece 5 has a clamping device 6 working by wedge principle ina manner known per se, which tightens around pile 7. Clamping device 6can, for instance, be opened and tightened by a hydraulic arrangement,whereby change of grip in the pile, detachments and fixings can beeasily done from the cabin.

For control of the back and forth motion of mass 2, a steering pipe 9 isplaced between parts 21 and 5. To the primary side 20 of the cylindersmedium is conducted along line 14 in order to lift up the mass afterstroke. There is on the secondary side of the cylinders a gas filling,against which pressure fluid then pushes the piston The gas filling is,for instance, nitrogen and compressed to high pressure depending ondistance s, which the piston travels. By means of control unit 17 ithas, for instance, been possible to determine beforehand to whatpressure the primary side is restricted during back motion, where by acertain pressure is formed even on the secondary side of the cylinders.Pressure can be measured even from the secondary side and informationtransmitted to control unit 17. From valve arrangement 13 pressure fluidis conducted along line 14 to the primary side. Control unit 17 steersthe change valve 13 in line 14 to open and the mass starts to strikedownward. In this case the stroke length is adjusted with remote controlover control unit 17 by means of pressure line 14 control or by means ofpressure measured from secondary side. There is, for instance, incylinder 8 fixing spot a permanent magnet 11 and inside body 1 aproximity switch 10, whereby by means of the location detector formed bythese ones the position of the mass back motion can be detect ed. Bymeans of control unit 17 it is possible to choose how far (distance s)the mass is returned for stroke. Pressure produced by hammering to thesecondary side of cylinder is determined on basis of the return travel slength According to FIG. 3 pressure P on secondary side grows as thetravel gets longer. Filling beforehand (e.g. nitrogen) on secondary sideis Pe. Wanted hammering energy is received defining how far the mass isconducted by means of pressure fluid. Or otherwise, to which pressurevalue the pressure to be fed to primary side can be allowed to risebefore the mass back motion is stopped. To produce a stroke from primaryside 20 an exit for pressure fluid is opened, where by the secondaryside gas pressure suddenly pushes piston 16 and then also the piston rodout, while mass 2 moves the same distance. The impact energy is E.E = ∫₀^(S)AF(s)  𝕕swhere A is the piston cross-sectional area

-   -   the opposing pressure of primary side is not noticed in the        formula)

When pre-pressure Pe is known striking energy can be producedcalculating from the formula, using FIG. 3 function, by which value ofdistance s it found out and the back motion is adjusted as S.

By means of control centre 17 the position of mass 2 is observed andmanipulated by means of detectors 10 and 11 and by the pressure detectorin line 14, which is the pressure to be fed to primary side 20 and equalalso to the primary side pressure when it's not the question of strokemotion. It is possible to check from line 14 pressure prevailing onprimary side.

The most simple stroke length regulation (=hammering energy) takes placeby moving detector 10 on body 1 surface. When it reaches magnet 11 thevalve changes direction in arrangement 13. It is, however, moreadvantageous to use the location detecting arrangement, where detectorsare not moved. Such a detecting and observing arrangement is chosen thatby means of detector 10 the distances of part 11 in regard to detector10 can be indicated to unit 17 on the whole stroke distance that comesinto question. Induction detectors, proximity switches or other locationindicating detecting arrangements, known per se, can be used.

Alternatively the fluid pressure of primary side or secondary side isdetected and when the set pressure is reached, control unit 17 givesvalve an impulse to change direction of flow for the stroke. Pressurevalve is most suitably set from the cabin by remote control, whereby thesize of stroke is easy to choose for each situation.

FIG. 2 shows a hammering device in an alternative way i.e. turned 180°,for instance in an excavator boom, whereby piles are hammered up fromthe ground. It is possible to manage with one clamping piece andclamping component arrangement 6. By means of the excavator boom it ispossible to maintain pre-pressure in the pile by lifting the deviceupward by means of the boom with proper force uninterruptedly. Likewisepre-pressure downward is maintained in hammering piles into the ground.Pre-pressure force is transmitted over damping rubbers 3,4 and its sizemust be restricted in order to avoid leakage of rubbers.

If intensification of strokes is required, it is possible to arrangeinside mass 2 a moving mass 17 and for it a space for moving greaterthan the volume required by mass 17. For instance, mass 17 has distanced, and after having done it, it dashes against the end of its space.This collision takes place with minor delay of in regard to thecollision with mass 2 counterpart 5. The double stroke intensifies thestroke effect of the mass. Mass 17 can be in solid form, liquid or heavygranulate. Double stroke takes place with the device hammering bothdownward and upward.

In FIGS. 1 and 2 cylinders 8 are on mass outside, they can also becloser to steering pipe 9 and from their other end fixed to mass 2 end.Then the device becomes as to its diameter clearly smaller if body 1 is,for instance, a pipe. Indeed, the structural height grows a little.

1. A hammering device comprising a body (1) from which the device can beconnected to a working machine, for instance, a stroke-transmittingpiece (5) fixed in body (1) taking the strokes of moving and hammeringmass (2) and transmitting the strokes to a pile (7) or similar to behammered into or pulled up from the ground or to a tool connected to thedevice, whereby between piece (5) and pile (7) or the tool a clamp (6)is applied, by means of which pile (7) or tool is grasped and in whichdevice strokes transmitting piece (5) and hammering mass (2) arering-shaped and pile (7) to be hammered is arranged to travel throughthe ring-shaped parts, characterized in that the device includesring-mass (2) moving cylinders (8), by means of which the back-motion ofring-mass can be carried out conducting the fluid pressure to haveeffect on piston (6) of said cylinders on primary side (20), and bymeans of which cylinders the hammering motion of mass (2) can be carriedout compressing the gas on the secondary side of cylinders 8 into wantedpressure by means of fluid pressure conducted to primary side (20),whereby hammering motion is carried out discharging the fluid pressurefrom primary side (20) of the cylinders.
 2. A hammering device accordingto claim 1 characterized in that cylinders (8) are from their other endfixed to mass (2).
 3. A hammering device according to claim 1characterized in that mass (2) hammering energy can be regulated bymeans of the length (s) of mass (2) back-motion.
 4. A hammering deviceaccording to claim 1 characterized in that mass (2) hammering energy canbe regulated adjusting the pressure (p) of cylinder (8) secondary side.5. A hammering device according to claim 1 characterized in that to mass(2) additional mass (17) is arranged moving in regard to mass (2), thehammering impact of which on piece (5) takes place with delay in regardthe stroke of mass (2) due to distance (d).
 6. A hammering deviceaccording to claim characterized in that the device can be turned 180°,both for hammering in and pulling out piles from the ground.
 7. Ahammering device according to claim 1 characterized in that the devicehas a control unit (17, by means of which the hammering energy of mass(2) can be regulated by remote control.
 8. A hammering device accordingto claim 1 characterized in that the device has a pipe (9) steering mass(2) and running through the centre hole of mass (2).
 9. A hammeringdevice according to claim 1 characterized in that in piece (5)pre-pressure in hammering direction can be arranged by means of theworking machine or similar.